Bandsaw question/adjustment help needed

Matt Vanderpan

Matt Vanderpan

Active member
Here is my dilemma... I just bought a new blade for my Jet JBS-14
I got it on and adjusted so it was rolling in the middle of the wheel,
I got the guides set and the rear roller wheels set too. I turned it on let it run and
the bottom rubber band popped off. It happened a couple more times and then
i thought I had it. It ran for a minute or two and the rubber band stayed on
but it did notice that the band was lifting vertical off of the bottom wheel from
about the 10 o'clock to 2 o'clock position. It was lifting a good 3/4"-1".
I tried cutting some wood with it and it worked fine for about 30 minutes.
Then the lower rubber band came off and was shredded by the new blade.

Was the rubber band worn out and that is why it kept rising up and popping off
or was it out of adjustment? I hope one of you can decipher my explanation.


-Matt
 
They are called "tires". It sounds like it wore out and stretched. The bottom wheel is the drive wheel, did you have the tension cranked way up too tight?
 
Never had that happen. Usually my bands are to old and hard to do that. What I would suggest is put a light, very light amount of rubber cement on the wheel before putting on a new rubber band. I wonder if the rubber band was over sized. Over tensioning could possibly do it also. With a new blade the teeth could be picking up the rubber where the old one didn't. Again rubber cement or contact cement could solve that.
 
They are called "tires". It sounds like it wore out and stretched. The bottom wheel is the drive wheel, did you have the tension cranked way up too tight?
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I dont think so, It was about as tight as I had it on the old blade. When adjusting....how tight is too tight and how tight is just right? How much do new tires cost to replace? do they come in a pair?


I like the rubber cement idea too thanks for the tip.
 
They aren't real expensive. When you tracked your blade, did yo have it so the teeth were just off center? The tires have a little dome in the center and that should be under the center of the blade pretty much. Tension, without a gauge is a guess. I tension mine until they just "twang"....start low and thumb the blade like a guitar string while tightening the tension...thud, thud ,thud,thud, twang and stop. You can then tell by your cut whether it needs a bit more. Some tires require cement and some don't.
 
I tension mine until they just "twang"....start low and thumb the blade like a guitar string while tightening the tension...thud, thud ,thud,thud, twang and stop.
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That sounds so dumb yet it is brilliant because it is so easy to understand.

IT reminds me of the old days when we had backup memory disk drives that were driven by a 110v, 1/2 hp, motor and a thin drive belt. They had difficult instructions for tensioning those belts. It involved making sure it was not spinning, using a spring scale and measuring the deflection of the belt while the scale was reading six pounds. No one did it that way though.

New official instructions eventually replaced these. The new instructions- Put the new belt on. Push on the middle of it with your thumb. If it is too loose, tighten it and if it is too tight, loosen it.

Those old disks weighed a lot and had admonitions to not move them till they spun down. It was a single double sided 28" disk in a heavy case and spun at 14,000 rpm. It held practically nothing in memory though.

Bob
 
Bob, rocket science is rocket science, not because it is hard...it's because they make the instructions so hard you have to have years of schooling to understand them. Least common denominator is usually the best. Thank God for instructions now-days with cartoon pictures...I can't read Chinese.
 
Matt

Like Lee said it sounds like an issue with worn out tires. Are they the old style black neoprene rubber or the newer orange or blue polyurethane tires. If they are the black rubber ones you could reglue them although I suspct they just need replacing. A lot of folks like the new polyurethane tires since they are easier to install and don't need glue. I prefer the old neo rubber ones since they can be crowned. The wheels have a crown built in but you can true rubber ones like a car tire yileding a saw that runs very true and tracks flawlessly.
 
I have always glued my bandsaw tires on. I have bumped up the HP with a different motor and I push a lot of 2-3" wood through it fast. The tires will not stay on with out the glue.

Mark F. Cheney
 
Matt

Like Lee said it sounds like an issue with worn out tires. Are they the old style black neoprene rubber or the newer orange or blue polyurethane tires. If they are the black rubber ones you could reglue them although I suspct they just need replacing. A lot of folks like the new polyurethane tires since they are easier to install and don't need glue. I prefer the old neo rubber ones since they can be crowned. The wheels have a crown built in but you can true rubber ones like a car tire yileding a saw that runs very true and tracks flawlessly.
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Yea they were the old black kind. There was virtually no elasticity in the old one and they were very cracked in a few places. I went ahead and ordered a new poly set that should be here mid this week. Before my new blade shredded the old tire, the saw cut like a light saber!!! I went from a 6TPI @3/4" thick to 4TPI 3/8 thick. I am looking forward to having it back in business.
 
Does your saw have a tensioning guide on the back of the top wheel where the tensioner handle is? My old Delta 14 has one.

If so it will give you a tension reading based on blade width. That usually gets you a pretty reliable degree of tension for the blade being used.

I'd bet that the switch from 6 to 4-TPI was the reason you saw a dramatic improvement in cutting performance.
 
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